Interface ServicePlan<DateType>

interface ServicePlan<DateType extends Date | string = string> {
    activeFrom: null | DateType;
    dataCategoryMapping: null | DataCategoryMapping;
    dataPoolUsage?: {
        accountNumber: string;
        dataBlocks: null | DataPoolUsage<DateType>[];
        lastUpdated: DateType;
    };
    isMobilePlan: boolean;
    isoCurrencyCode: null
    | string;
    isOptedIntoOverage: boolean;
    overageDescription: null | string;
    overageLine: OverageLine;
    overageLineDeactivatedDate: null | DateType;
    overageName: null | string;
    productId: null | string;
    subscriptionActiveFrom: null | DateType;
    subscriptionEndDate: null | DateType;
    usageLimitGB: number;
}